Fuse cut-out.



E. R. UARICHOFF.

FUSE CUT-OUT.

APPLICATION FILED 001212, 1911.

1,055,877. Patented Mar. 11,1913.

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UNITED STATES PATENT-canon.

EUGENE R. CABICHOFI, OF SCHENECTADY, NEW YORK, ASSIGN'OB To GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK. j

FUSE cur-our.

Specification o! Letterslatent. Patented-Mar. 11,1913.

Application filed October 12, 1911. Serial No. 854,229.

To all whom z't may ctmcem':

Be it knownthat I, EU E E R. CAmcHorF, a citizen of the-United-"St'ates, residing at Schenectady, county of Schenectady, State of New York, have-invented certain new and useful Im rovements in Fuse Cut-Outs, of which the ollowing is a specification.

My invention relates to fuse cut-outs for protecting circuits of 'comparativel high voltage and large currents audits o ject is to provide a .fuse which will rupture such a circuit upon an overload more positively and instantaneously than the fuses emp oyed heretofore.

I obtain the desired result by forming the.

fuse member so that its current carrying capacity is reduced at a plurality of points alon its length and providing means for ejecting the portion of said member between said points upon rupture at said points. With this construction the-fuse is ruptured upon overload at two points and the portion between those points bodily expelled so as to leavea wide-gap.' This produces less gas than the ordinary fuse, in which rupture occurs at a single point so that. it is necessary to burn away a considerable length of the fuse before the arc breaks. Furthermore, I have found by oscillograph tests that a fuse constructed in accordance with my invention breaks a circuit immediately and finally under conditions in which a fuse of the ordinary construction allows the circuit to reestablish itself one or more times through the conductive gases of combustion. Furthermore, if a magnetic blow-out is employed for expelling the ruptured portion, it; may be arranged very efficiently with a fuse ofmy improved construction as will be hereinafter pointed out.

My invention will best be understood by reference to the accompanying drawings in which Figure 1 shows a side elevation, with the casing in cross-section, of a fuse cut-out arranged in accordance with my invention and Fig. 2 shows an enlarged plan viewof the fuse member.

In the particular embodiment of my in vention shown in the drawings A represents the fuse member which has its current carrying capacity reduced at two points by holes a, a, which reduce the cross-section at this point as is shown in Fig. 2. The ends of of the fuse member.

this fuse. member are clamped in suitable termmal blocks 'B, B by-meansof wedges b, b which are drawn up by knurled screws D, D represent blow-out coils at ends of the fuse and in series therewith. From these coils magnetic pole pieces E (shown in dotted lines in Fig. 1) extend adacent to the points a, a ofreduced capacity It will be understood that there 1s a pair of pole pieces E o posite each other for each'coil D, so that t e flux asses between the pole pieces of each pair 1n a direction perpendicular to theplane of the paper in Fig. 1.

F, F represent the usual insulating barriers forming the arc chuteif The operation of the fuse cut-out will be obvious from the foregoin description.

Upon an overload or short circuit the fuse.

member A is ruptured at the points a, a, and the portlon between these points is ejected by the magnetic fields formed atv these points between the pairs of 'pole pieces E. Thus a wide gap is-formed inthe circuit, and the circuit is cons'e uentl immediately and positively rupture with a comparatively small production of gas 1 It will be noted that the tips of the pole pieces E may be brought directly opposite the points a, a on the fuse member so that strong fields are producedprecisely at the points where they are needed, while in the fuse of ordinary construction, W-ith'a' single hole at its center, the pole pieces E extending from opposite ends of the fuse member must be kept separate and cannot be brought together without impairing theinsulation, so thatthey-c'annot'extend to the exact center of the fuse member at which rupture takes place in theordinary construction.

I do not desire to limit myselfto the particular arrangement and' construction of parts shown and described butaim' in the accompanying claims to cover all modifications which are within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

- esich end of said fuse memben in series theretherewith, @nd'magnetic pole pi'ces extend- .ing a plurality of portions in series of re-.

duced' current carrying capacity, coils at with, magnetic :pole iecesextending from said coils to'points' a; 1acer'1tj-to said ortions of reduced capacity, and; insulating arriers extending fronieach'end of said filse member past said coils and fol'ming'an arc dii'ecting chute between said pole pieces.

In witness whereof, I have hereunto" set my hand this 11th day ofOctober, 1911.

Witnesses:v I BENJAMINVBZHULL,

v IIELENIORFOH).

- EUGENE CARICHOFF. 

